【作者】 孙伟；

【导师】 李林川；

【作者基本信息】 天津大学 ， 电力系统及其自动化， 2004， 硕士

【摘要】 无功功率的分布不仅与电压幅值有着密切的关系，而且与有功功率的损耗也有着密切的关系。因而电力系统无功优化问题是电力系统研究领域的一个重要课题，但是近年来由于电力市场的实行，传统的无功优化模型不能够适应电力市场的要求，研究适应电力市场要求的无功优化模型具有较重要的理论意义和较大的实用价值。在传统的电力系统无功优化的数学模型中，一般以系统有功网损最小为目标函数，为了适应电力市场的实际情况，本文提出的无功优化数学模型不仅考虑了系统有功损耗还考虑了无功功率的费用。在算法上采用了具有较强的全局寻优能力和较好的适应性的新算法――遗传算法和Alopex方法相结合的算法作为无功优化的求解方法。为了减少变压器分接头动作次数，延长设备使用寿命，本文提出了一种分段计算的方法来满足一天的无功优化。该方法根据一天的负荷水平和变化趋势以及一天内变压器分接头动作次数的限制，将一天划分为几个分段然后对每一个分段分别进行无功优化计算。这种方法能够比较容易地满足一天内变压器分接头动作次数的限制，而且对于大部分时间段只进行发电机端电压和补偿容量的优化计算，这样便减小了计算时间。通过对算例的计算结果表明，本文提出的方法是可行的。更多还原

【Abstract】 The distribution of reactive power has close relations with not only voltage amplitude but also the power loss. So the reactive power optimization problem is an important subject in the research domain of power system, but because of the realization of power market in recent years, the traditional reactive power optimization model can’t adapt to the requirements of power market, the study on reactive power optimization model which can adapt to the requirements of power market has theoretical meaning and practical value. In the traditional mathematical model of reactive power optimization, usually taking the minimization of the power loss as the objective function, in order to adapt to the actual conditions in the power market, the mathematical model of reactive power optimization described in this paper considers not only system power loss but also the price of the reactive power. We use a new algorithm which has the ability of global search and better adaptability―Genetic Algorithm integrated with Alopex in this paper as the solution method.In order to reduce the switching operations of transformer, increase the service time of equipments, we proposed a sectionalized based reactive power optimization method in the paper to satisfy the requirements of one-day reactive power optimization, this method divides one day into several sections and performs reactive power optimization separately according to the load level, its changing tread and the maximum allowable number of switching operations. This method can meet constraints of the maximum allowable number of switching operations easily, moreover optimization calculation only includes voltage of generator and compensation capacity for most time segments, so it improves calculation speed. The results of the calculation examples demonstrate that the method described in the paper is feasible.更多还原